In a precise series of raids, Israeli Army troops today forcibly evacuated most of the 2,000 militant settlers from this northern Sinai development town and immediately began bulldozing the sprawling Mediterranean seaside town into the sand dunes.

Four days before Israel is to turn over the last section of the occupied Sinai Peninsula to Egypt, huge earth-moving machines rumbled through the town late into the night, reducing scores of neat, stucco villas and town houses into grotesque piles of rubble. As the houses fell, a diehard band of about 200 infuriated opponents retreated to rooftop redoubts and threatened to battle the already weary and emotionally wrung-out Israeli soldiers, who in a few short hours had transformed the once-thriving desert oasis into rubble.

The troops pulled back from a final confrontation as darkness fell, but were expected to complete a mopping-up operation Thursday.

For the most part, the opponents of Sunday's scheduled withdrawal from the last third of the Sinai offered only passive, if vocal, resistance to the evacuation, but there were some ugly clashes in which holdouts attacked soldiers with rocks and sandbags and attempted to knock them off ladders used to assault the heavily fortified roofs.

The steadily building drama of a threatened suicide by about half a dozen extremists barricaded in an underground bomb shelter failed to materialize when their leader, U.S.-born Rabbi Meir Kahane, was helicoptered into Yamit after a hurried trip from abroad for negotiations with the Israeli government that ended in significant concessions by the government.

The young, mostly American-born supporters of the Jewish Defense League rescinded their threat to commit suicide one by one after Israeli authorities promised them that they could remain in their heavily fortified bunker until the turnover of the Sinai on Sunday. Army southern region commander Brig. Gen. Chaim Erez also promised to urge the government of Prime Minister Menachem Begin to request Egyptian permission for the religious and nationalist protesters to remain in a nearby synagogue and yeshiva, or religious school.

A smaller group of secular nationalists, most of them university students, remained holed up in the top of a hollow spire of a towering monument to Israeli soldiers killed in the region in the 1967 war. But they were expected to be forced down overnight.

The way was cleared for the oft-postponed evacuation of Yamit after Begin's Cabinet, apparently satisfied by the receipt of an Egyptian reaffirmation of its commitment to the Camp David peace accords, voted to proceed with the Sinai withdrawal on schedule.

While the opponents of the withdrawal--almost all relatively recent squatters who took over homes abandoned by the original residents of Yamit--were aware of a heavy Army presence, few seemed to expect the suddenness and almost clinically efficient thoroughness of the early-afternoon Army sweep.

Surprisingly, for an essentially military operation of force, there were no reported serious injuries, and rows of ambulances standing by on a nearby parking lot remained idle through the evacuation, which was code-named "Red Dove."

Obviously well-rehearsed for the operation, units of the Army and national police force attacked the houses and apartments in teams of 10 or 12 soldiers. The teams included both men and women and were top-heavy with experienced and senior grade officers, many with riot- control or antiterrorist training.

One of the day's most dramatic episodes occurred when a small group of Jewish Defense League militants, who were said to have been armed with automatic rifles and hand grenades, were routed out of a spacious California-style villa that stood apart from the compact stucco town houses characteristic of Yamit.

A police task force was raised onto the roof of the villa inside a metal cage hoisted by a construction crane, while other policemen clawed their way up a destroyed staircase inside the building and sprayed the protesters with foam pumped from nearby fire trucks.

The cage was lowered onto the roof under a shower of rocks, and policemen and settlers engaged in hand-to-hand combat before the house was seized. Shortly afterward, the house was bulldozed into rubble.

In a clash on one roof in the center of town, settlers poured cooking oil and sand on soldiers attempting to scale a ladder to the roof, and struck at the top of the ladder with metal bars as the troops neared the top. The assault force eventually withdrew from the apartment block, amid cheers from its defenders.

At the nearby Yamit Motel, site of the bunker of Kahane's supporters, Sinai withdrawal opponents shouted "Nazis, Nazis!" at soldiers who occupied the roof, and one woman threatened to jump off the edge if soldiers came any closer. Below, the the doorway, an orthodox Jew wearing a shroud lay prostrate in the sand, crying, as his two small children sat beside him with bewildered looks on their faces. Some demonstrators confronted soldiers with infants in their arms.

Geula Cohen, a member of the Knesset, or parliament, from the ultranationalist Tehyia Party, walked through the confusion seemingly dazed.

"This is why there will be another war in the Sinai," she said. "Look around you, and you will know that another war is inevitable."

At one stage of the confrontation at the bunker of the Kahane supporters, security forces brought up two tracked hydraulic bits usually used to break rock on excavation sites and positioned them as if to punch holes in the bomb shelter's thick concrete walls. Riot police stood by with hoses ready to flood the chamber to force out the holdouts.

Earlier in the day, the mothers of two young women barricaded in the bunker went to Jerusalem to visit with Begin and senior Cabinet ministers, presenting them with a letter from the Kahane holdouts demanding a cancellation of the withdrawal and demanding that Jerusalem's eastern, predominantly Arab, quarter never be discussed in negotiations with Egypt.

As early as 4 a.m. tensions had begun to rise among militant settlers when teams of soldiers, armed with detailed diagrams of Yamit, began occupying roofs of apartment blocks. The apparent purpose was to avoid direct confrontation inside the apartments, where most of the women and children were.

During one raid, when troops mistakenly occupied an apartment roof they thought was vacant, loudspeakers rigged by the settlers blared warnings of an imminent assault, and settlers screamed, "If you don't want violence, get back." Less than two hours later, scores of settlers stood on the roof, chanting prayers.

The town took on a surrealistic atmosphere a few minutes later when the same loudspeakers announced the normal start of school for Yamit children in makeshift classrooms, and the local cooperative supermarket opened. On the broad pedestrian malls of Yamit, soldiers mingled easily with settlers, sharing coffee in the preedawn darkness, and often disagreeing in political discusssions.

When the evacuation began, scores of heavy trucks entered the town while young Army recruits loaded furniture into the vehicles, marking it with destinations of the displaced settlers.